1. Field of the Invention
The present invention relates to a paper splicing device for splicing paper at a paper feeder of a rotary press for continually supplying paper by splicing paper web, i.e. a so-called “on the fly” paper splicing device. With on the fly splicing devices, pasting units for paper splicing are provided using adhesive or double-sided adhesive tape at the surface at the lead edge of the paper in order to splice the paper. A paper roll where this lead edge is held on standby in such a manner that the lead edge is temporarily tacked against the peripheral surface is then driven to rotate so that the peripheral surface moves at substantially the same speed as paper web when the paper web is being consumed, and the paper web being consumed is made to make contact with the lead edge of the rotatably driven paper roll by the pressing member and is spliced.
2. Description of the Background
With related paper web splicing devices, the pressing member pressed by the pressing means moves in the direction of the peripheral surface of the paper roll, and the pressing member rebounds due to the reactive force due to the impact of the pressing member after the pressing member collides via the running paper web. This rebounding is repeated, and it therefore takes time until the pressing member stops in a stable state with the pressing force being appropriate. The pressing force of the pressing member for pressing the running paper web onto the peripheral surface of the paper roll is therefore of an inconsistent strength, which in turn causes the paper splicing to malfunction. FIG. 9 is a graph showing the relationship between displacement and time elapsed for a pressing member of this kind of related paper splicing device.
Paper splicing devices having means for suppressing rebounding due to the pressing impact of the pressing member on the surface of the paper roll have been considered in order to resolve these problems, and have been made public as shown in Japanese Laid-open Patent Publication Hei. 6-71954 (related art 1) and Japanese Patent Publication No. 2929376 (related art 2).
The paper splicing device shown in related art 1 comprises a first pressing means provided linked with a pressing member and a coupling member supporting the pressing member, the pressing member being made to move by the operation of the coupling member, and a second pressing means provided connected to the coupling member, acting after the action of the first pressing means, and suppressing rebounding of the pressing member made to move by the first pressing means.
The first pressing means of related art 1 rapidly moves the pressing member towards the running paper web so that the running paper web is pressed against the peripheral surface of the rotatably driven paper roll. The second pressing means is also provided to prevent rebounding of the pressing member occurring while the pressing member collides with the peripheral surface of the paper roll during pressing of the paper web. The second pressing means acts to suppress rebounding of the pressing member from the peripheral surface of the paper roll after the pressing member is made to collide with the paper roll by the first pressing means.
The paper splicing device shown in related art 2 comprises a pressing member and a coupling member supporting the pressing member, first pressing means provided linked with the coupling means and causing the pressing member to move as a result of the action of the coupling member, and damping means, provided in the vicinity of a shaft causing the pressing member to move using angular displacement within the coupling member, and coming into contact with this shaft when the shaft is elastically deformed so as to act to dampen angular displacement of the shaft. In addition to this configuration there is also further provided second pressing means provided so as to be coupled with the coupling member and acting after the action of the first pressing means, so as to reinforce the pressing force of the pressing member caused to move by the first pressing means.
The first pressing means of related art 2 rapidly moves the pressing member towards the running paper web so that the running paper web is pressed against the peripheral surface of the rotatably driven paper roll. When the paper web is pressed, the pressing member first makes contact with the running paper web, a force is then exerted from the paper web in the direction of running of the paper web, and the shaft within the coupling member then elastically deforms as a result of this force, making contact with the damping member of the damping means. The pressing member then collides with the surface of the paper roll so as to bring about a reactive force. The pressing member therefore attempts to rebound due to this reactive force but frictional force acts between the shaft within the coupling member and the damping member so as to suppress the angle of displacement between this shaft and the pressing member.
With the configuration provided with the second pressing means, the second pressing means acts in cooperation with the damping means to suppress rebounding of the pressing member from the surface of the paper roll and strengthens the pressing on the peripheral surface of the paper roll after the pressing member is made to collide with the paper roll by the first pressing means.
In related art 1 and related art 2, rebound preventing means acting to resist the rebounding operation are provided as means for suppressing the rebounding of the pressing member and the relationship between the amount of displacement and the elapsed time for the pressing member of the paper splicing device with this kind of configuration is shown in the graph in FIG. 8. FIG. 8 shows that the occurrence of rebounding is suppressed to a relatively short duration after the pressing member collides with the peripheral surface of the paper roll via the running paper web.
However, the impact force with which the pressing member first collides is not suppressed in any way and the reactive force proportional to the magnitude of the impact force therefore acts as is. The pressing member is therefore made to stop and there is therefore the problem that it takes a little time before the pressing force stabilizes to an appropriate amount. Therefore, during this time, the pressing force of the pressing member for pushing the running paper web onto the peripheral surface of the paper roll is inconsistent in strength, which causes paper splicing of the paper web and the lead edge of the paper roll to be defective. The impact due to the collision of the pressing member is directly applied to the running paper web and the peripheral surface of the rotatably driven paper roll and the tension of the paper web during running therefore rises rapidly causing instability. This causes the paper splicing to be unstable and causes the splicing precision to fall.
With the damping means disclosed in related art 2, the shaft of the coupling member supporting the pressing member is elastically deformed due to the force exerted from the running paper web while the pressing means is in contact with the running paper web and the elastically deformed portion is dampened by frictional resistance. There is also a problem that deformation of and damage to parts occurs more easily due to repeating a paper splicing operation where pressure is applied to the paper splicing device for every paper splicing operation, with the lifespan of the paper splicing device therefore falling as a result.